Reduce build warnings

src/mir/builder/core_context.rs

@@ -92,11 +92,13 @@ impl CoreContext {
     }
 
     /// Peek at the next ValueId without consuming it
+    #[allow(dead_code)]
     pub fn peek_next_value(&self) -> ValueId {
         self.value_gen.peek_next()
     }
 
     /// Peek at the next BasicBlockId without consuming it
+    #[allow(dead_code)]
     pub fn peek_next_block(&self) -> BasicBlockId {
         self.block_gen.peek_next()
     }